The aims of the lectures are:
(i) to explain what concentration fluctuations are;
(ii) to illustrate their importance in environmental impact assessment;
(iii) to discuss some factors relevant to the quantitative description of concentration fluctuations;
(iv) to describe a framework for this description.
It will be clear from the lectures, and from others later in the Workshop that there is rapidly increasing awareness of the importance of concentration fluctuations and, consequently, much research activity into their properties. Not surprisingly there are still many unsolved problems, and a by-product of the lectures will be to highlight one or two of the most important
